Ski bindings

ABSTRACT

Ski binding units for fastening a ski boot at the toe and heel of the boot. The toe binding unit applies cantilever loading to the toe of the boot through an abutment which overlaps the toe of the boot. The heel binding unit supports the heel on roller bearings and yieldably clamps the heel against the bearings by means of a snap action spring blade. The heel unit releases the heel of the boot laterally while the toe pivots about the toe unit, when a predetermined lateral force is applied. The heel unit is capable of releasing the boot vertically when predetermined forces are applied to the respective units. The heel binding includes a clamping roller that engages a cam surface on the heel of the boot. Lateral displacement of the heel stresses the blade progressively unitl it snaps over to release the heel.

United States Patent 11 1 Wilkes NOV. 20, 1973 1 1 SKI BINDINGS [75] Inventor: DonaldF.Wilkes,Alburquerque,

N. Mex.

I73] Assignee: Rolamite, Incorporated, San

Francisco, Calif.

[22] Filed: Oct. 21, 1971 [2]] App]. No; 191,454

Related U.S. Application Data [63] Continuation-impart of Ser. No. 20,646, March 18, 1970, Pat. No. 3,687,470, and a continuation-in-part of Ser. No. 3,463, June 16, 1970, Pat. No. 3,671,052.

[52] U.S. Cl. 280/11.35 T [51 Int. Cl. A63c 9/00 [58] Field of Search 280/1 1.35 T

[5 6] References Cited UNITED STATES PATENTS 3,659,866 5/1972 Petersen 280/1 1.35 T 3,511,516 5/1970 Smocka 280/11.35 T 2,745,672 5/1956 Meier 280/1 1.35 T 3,497,230 2/1970 Mashioka.. 280/1 1.35 T 3,201,140 8/1965 Marker 280/1 1.35 T 3,338,587 8/1967 Wiley 280/1 1.35 T

Primary Examiner-Robert R. Song Attorney-Bums, Doane, Swecker & Mathis 57 ABSTRACT Ski binding units for fastening a ski boot at the toe and heel of the boot. The toe binding unit applies cantilever loading to the toe of the boot through an abutment which overlaps the toe of the boot. The heel binding unit supports the heel on roller bearings and yieldably clamps the heel against the bearings by means of a snap action spring blade. The heel unit releases the heel of the boot laterally while the toe pivots about the toe unit, when a predetermined lateral force is applied. The heel unit is capable of releasing the boot vertically when predetermined forces are applied to the respective units. The heel binding includes a clamping roller that engages a cam surface on the heel of the boot. Lateral displacement of the heel stresses the blade progressively until it snaps over to release the heel.

15 Claims, 36 Drawing Figures Pmimin-ncvzo 1973. 3773.344

SHEET 03 0F 12 FIG. 7

PATENTED NOV 20 I975 FIG. l2 I;

saw us or 2 Pmmnnuuvzo ma 3773344 saw our 12 PAIENTEUxnvzo I973 SHEET 08 12 3.773.344

FIG.2|

. SHEET 0F12 PATENTEDEUYZO 1975 PATENTEDNUV20 I973 SHEET llflF 12 FIG.29

SK] BINDINGS CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of my copending application Ser. No. 20,646, filed Mar. 18, 1970 US. Pat. No. 3,687,470, and is a continuation-inpart of my copending application Ser. No. 3,463, filed Jan. 16, 1970, now US. Pat. No. 3,671,052, entitled Ski Bindings.

BACKGROUND OF THE INVENTION This invention relates to ski bindings, and more particularly to releasable bindings whichallow the boot to separate from the ski when predetermined forces are applied to the skiers foot.

The principle purpose of a ski binding is to hold the boot firmly on the ski so that the movement of the skiers foot controls the position on the ski relative to the ground. If the skier encounters an obstacle, such as a slalom pole, or an exposed root, or if the skier experiences a severe fall, his foot may be twisted or flexed with such force that bones may be broken. Therefore, ski bindings are designed to release the boot at a force level that is less than that required for breaking any bones or injuring muscles or tissue.

The maximum forces that a skiers feet and legs can tolerate in the various directions are generally proportional to the weight of the skier. For example, large men skiers are capable of withstanding greater forces than are small women skiers. It is therefore necessary to provide adjustability of the force required for release. It is also necessary to a limited vertical displacement of the heel relative to the ski. The bindings, therefore, must be adjustable for the maximum allowable force required to release the skier.

Toe bindings have been proposed previously which allow the toe to release laterally in response to a predetermined force to avoid torsional injuries. Typically, bindings of this type utilize a spring biased detent which releases the boot toe laterally when lateral force overcomes the spring force. Bindings of this type do not reliably release at a selected force level because typically the boot must slide relative to the binding, but the variation in the frictional resistance between the boot and the binding is so great that the force required for lateral displacement is unpredictable.

Similarly, at the heel, lateral release with conventional bindings is uncertain because it is necessary for the heel of the boot to slide across the platform on which it is supported and the frictional resistance to lateral sliding varies greatly. For example, when the full weight of the skier is applied to the platform the frictional resistance would be relatively large, but if the ski is hitting the ground laterally while the skier is falling, it is possible that none of his weight is applied to the platform and the frictional resistance is much less. Typically, heel bindings that provide for lateral release operate by means of springs and the spring force adjustment for release does not take into account the variations in weight or load of the skier on the ski at the time when release is required.

A skier should be able to adjust the force limits for release of the bindings according to his weight, ability, degree of physical conditioning, and the condition that he expects to encounter. These adjustments fpreferably should be accomplished without the use of any special tools. Also, the bindings should allow the skier to readily fasten the boot into the bindings and the bindings should be capable of being released manually with very little effort.

SUMMARY OF THE INVENTION It is an object of this invention to provide improved devices for binding boots to skis.

Another object of this invention is to provide'ski bindings which effectively and reliably release the boot from the ski when a predetermined force is applied to the boot either laterally or perpendicularly with respect to the ski.

It is a further object of this invention to provide ski bindings which do not have irregular release characteristics caused by variations in frictional forces between the boot and the bindings.

A still further object of this invention is to provide bindings that can be readily fastened on the boot and manually released with a minimum of effort.

A further object of this invention is to provide ski bindings which can be adjusted without the use of special tools.

These objects are accomplished in accordance with preferred embodiments of the invention by a front binding unit and a rear binding unit which are secured on a ski. The front binding unit has a platform and an abutment which overlaps the top edge of a boot sole. The platform is spaced rearwardly toward the heel from the abutment, so that the sole is flexed in a cantilever arrangement when the heel is fastened in the heel binding unit.

The heel binding unit includes a resiliently flexible blade that is stressed to assume a transverse curvature which progressively increases toward one end of the blade. A clamping roller on the heel binding engages a cam surface on the sole to urge the sole against a platform spaced above the surface of the ski. The sole at the heel is supported on support rollers which allow lateral movement of the heel relative to the longitudinal axis of the ski. By a lever system, the spring blade acting through the clamping roller urges the boot heel against the support rollers.

Release of the heel in a perpendicular direction is accomplished by progressively deflecting the outer end of the blade until the blade snaps over to its opposite position thereby releasing the heel. Lateral release at the heel is accomplished by progressively camming the clamping roller upwardly along the cam surface on the heel in combination with the cam surfaces cooperating with the support rollers to cause deflection of the outer end of the blade until the lateral force ultimately casues the blade to snap over and to release the heel. The cam surfaces and the rollers cooperate to urge the bot to be centered on the ski. A shoulder on the from binding unit engages the front edge of the toe of the boot to cause the toe to slide from beneath the toe abutment as the heel rolls across the platform for lateral release, thus both the toe and the heel are released approximately simultaneously. The spring force of the blade in the heel binding is adjustable manually without the use of special tools.

DETAILED DESCRIPTION OF THE DRAWINGS Several preferred embodiments of the invention are illustrated in the accompanying drawings in which:

- unit along the line 15l5 in FIG. 12;

FIG. 1 is a top plan view showing schematically a ski boot fastened on a ski by toe and heel binding units in accordance with this invention;

FIG. 2 is a side elevational view showing schematically a ski boot fastened on a ski as in FIG. 1.;

FIG. 3 is a side elevational view of the heel binding unit of this invention; I

FIG. 4 is a top plan view of the heel binding unit;

FIG. 5 is an enlarged cross-sectional view of the heel binding unit along the line 5-5 of FIG. 4;

- FIG. 6 is an enlarged cross-sectional view of the heel binding unit along the line 6-6 of FIG. 3;

FIG. 7 is a cross-sectional view of the heel binding unit along the line 7- 7 in FIG. 5;

FIG. 8 is a front elevational view of the heel binding unit;

FIG. 9 is a cross-sectional view of the heel binding unit along the line 99 in FIG. 8;

FIG. 10 is a longitudinal cross-sectional view of the heel binding unit as in FIG. 5, but showing the unit adjusted for automatic cocking from the released position;

FIG. 11 is a longitudinal cross-sectional view as in FIG. 5, but showing the heel unit adjusted for manual cocking from the released position;

FIG. 12 is a side elevational view of a toe'binding unit in accordance with this invention;

FIG. 13 is a top plan view of the toe binding unit;

FIG. 14 is a cross-sectional view of a toe binding unit along the line 14-14 in FIG. 12;

FIG. 15 is a cross-sectional view of the toe binding FIG. 16 is a top plan view showing schematically a ski boot fastened on a ski by toe and heelbinding units in accordance with a second embodiment of this invention;

FIG. 17 is a side elevational view showing schematically a ski boot fastened on a ski as in FIG. 16',

FIG. 18 is a top plan view of the toe binding unit;

FIG. 19 is a top plan view of the toe support bracket;

FIG. 20 is a top plan view of the toe binding base plate; I v

7 FIG. 21 is a top plan view of the toe binding unit and the boot toe clip in accordance with the second preferred embodiment of this invention;

FIG. 22 is a side elevational view of the toe binding unit and boot toe clip as in FIG. 21;

FIG. 23 is a longitudinal cross-sectional view of the toe binding unit showing the boot toe clip clamped in the unit;

FIG. 31 is a detail perspective view' of the blade mounting bracket showing schematically the assembly of the elements;

FIG. 32 is a detail perspective view of the assembled DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Referring to FIGS. 1 and 2, a ski boot 2 is fastened to the upper surface of a ski 4 by a toe binding unit 6 I and a heel binding unit 8, which are illustrated sche- FIG. 24 is a rear elevational view of the boot heel late; p FIG. 25 is a bottom elevational view of the boot heel plate;

FIG. 26 is a longitudinal. cross-sectional view of the heel binding unit in accordance with the second preferred embodiment;

FIG. 27 is a side elevational view of the heel binding unit;

FIG. 28 is a cross-sectional view of the heel binding unit along-the line 28-28 in FIG. 27;

FIG. 29 is a cross-sectional view of the heel binding unit along the line 29-29 in FIG. 26;

FIG. 30v is a cross-sectional view of the heel binding unit along the line 30-30 in FIG. 26;

matically. An important purpose of safety bindings is to maintain the boot closely coupled to the ski for maximum control of the ski, while allowing the boot to be released, if a force is applied by the ski to the boot in a direction and with sufficient magnitude to injure the skier. For example, if the body of the skier suddenly is thrown forward in a fall, the boot should release upwardly at the heel as indicated by the arrow 10 in FIG. 2. Also, the bindings should allow release of the boot laterally, as shown by the arrows 14 in FIG. 1 if the ski should he suddenly deflected, for example by an exposed root or tree limb.

The heel binding unit, as shown in FIGS. 3 to 11, includes a base plate 16 which is secured to the surface of the ski 4 by a pair of screws 18. The screws 18 extend through slots 20 in the base plate 16 and the surface of the plate surrounding the slots 20 has transverse serrations which cooperate with corresponding serrations on the bottom surface of a washer 22 to hold the base plate at a selected position longitudinally on the surface of the ski 4, as shown in FIGS. 5 and 6.

The base plate has a pair of upright brackets 24 struck from the plate 16, as shown in FIGS. 6 and 8. The brackets 24 have aligned slots 26 for receiving and journaling shafts 28 projecting outwardly from opposite ends of a roller 30. A second roller 32 is similarly supported on the base plate 16 at the opposite side, as shown in FIG. 6. The rollers 30 and 32 are retained in place by a cover plate 34 which is welded or otherwise secured to the base plate 16. The cover plate 34 includes rectangular openings 36 through which the upper portions of the respective rollers extend. As shown in FIG. 8, the edges of the opening 36 fit closely against the surface of the rollers 30 and 32, so that as the roller rotates, any 'snow or foreign material is scrapped from the surface of the roller.

The cover plate 34 also has a pair of longitudinal slots 38 which are aligned with corresponding slots in the base plate 16. Attachment screws 40 extend through the slots 38 and into the ski 4 to secure the base plate and cover plate to the ski. 1

The base plate 16 also includes an upright boot stop 42. The boot stop 42 has a guide slot 44 with a horizontal leg adjacent the surface of the ski and an upwardly curved leg. A rod 46 extends through the slot and is movable along the slot. The rod 46 also extends through aligned holes in a step lever 48 which projects forwardly. The base plate 16 has an opening around the lever 48 so that the forward end of the lever rests on the surface of the ski 4. The cover plate 34 has a raised shield 50 for retaining the outer end of the lever adjacent the surface of the ski. A boot stop spring 52 is secured in a pair of notches 54 in the lever 48 and extends upwardly to engage the top of the boot stop 42 when the lever is in the position shown in FIG. 5. The spring 52 is spaced from the front surface of the boot stop 42 and resiliently urges the heel of the boot forwardly toward the toe binding unit.

As shown in FIGS. 5, 6 and 7, a yoke 56 is pivotally mounted on opposite ends of the rod 46. The yoke 56 has a sleeve 58 at its upper end and a shaft 60 is supported for rotation in the sleeve 58. The shaft 60 supports a housing 62 (FIG. 5) which includes opposite side walls 64, a top wall 66, and a front wall 68. The shaft 60 extends through arcuate slots in each side wall 64. As shown in FIG. 7, the outer ends of the shaft 60 are provided with pinions 72. The side walls 64 are offset outwardly and arcuate racks 74 on the upper side of the slots 70 are engaged with the pinions 72 while the shaft 60 bears against the lower edge of the slots 70.

The position of the shaft 60 relative to the housing 62 is controlled by means of a worm 76 which meshes with a gear 78 formed on the shaft 60. A saddle 80 is supported on the shaft 60 and wrapped under the worm 76, as shown in FIG. 9. The worm 76 has a head 82 with a spherical outer surface which is received in a corresponding socket 84 in the front wall 68 of the housing. The head 82 isretained in the socket 84 by a slide 86 which is secured to the front wall 68. The slide 86 has flanges along opposite sides which are received in channels 88 formed in the front wall 68 of the housing. The slide 86 has a longitudinal slot 90 with spherical side walls which correspond to the size and shape of the head 82. Thus, as the worm 76 swings from the position shown in FIG. 5 to the position shown in FIG. 9, the spherical shape of the head and the corresponding socket 84 and slot 90 allow the worm to swing while resisting longitudinal displacement of the worm. The front of the slot 90 is wide enough to allow the insertion of a wrench for rotating the worm 76, as shown in FIG. 8. The slide 86 is displaced relative to the channels 88 by means of a screw 92. The screw is joumalled along one side on the front wall 68 of the housing and meshes with screw threads formed in the inner surface of the slide 86. Rotation of the screw 92 displaces the slide 86 upward or downward relative to the front wall 68.

The slide 86 supports a clamping roller 94 for rotation. A boot heel 96 is shown in phantom lines in FIGS. 5 and 8. The upper surface of the heel has a V-shaped cam surface 98 which is engaged by the roller 94. The bottom of the heel 96 rests on the surface of the rollers 30 and 32. The height of the roller 94 is adjusted by means of the screw 92 to accommodate the thickness of the boot heel when the roller is centered between the cam surfaces 98.

' Spring bias for resisting displacement of the clamping roller 94 away from the support rollers 30 by the boot heel 96, is provided by a resiliently flexible snap action blade 100. The blade when mounted in accordance with this invention has the characteristics of resisting deflection of the outer end of the blade 102 with progressively greater force until the blade snaps over from one bistable position to the other. The blade thus is unlike conventional snap action devices in which resistance to deflection decreases as the blade approaches a mid position between both bistable positions. The characteristics of the snap action blade are described more fully in my US. Pat. No. 3,543,595, issued Dec. 1, 1970. v

The blade 100 has an arcuate edge 104 which is received in the V-shaped, arcuate groove 106 in a reactor 108. Opposite ends of the reactor 108 have rectangular projections 110 which are received in corresponding grooves in an elongated tension bar 114. The grooves and projections cooperate to resist pivoting movement of the reactor 108 relative to the tension bar 114, but allow adjustment of the spacing between the reactor and tension bar. This adjustment is accomplished by means of a pair of adjustment screws 1 16which extend through the tension bar and engage the front side of the reactor 108. The tension bar 114 is attached to the top wall 66 of the housing by screws 118 which engage arms 120 projecting forwardly from the tension bar 114.

The blade 100 has a pair of tabs 122 extending forwardly at opposite ends of the arcuate edge 104. The tabs 122 each extend through a slot at the end of the tension bar 114 and the end of the tab 122 is bent up over the front'edge of the bar 114 and welded to the top of the bar, as shown in FIG. 7. The blade 100 is stressed by turning the screws 116 to displace the reactor 108 relative to the tension bar to induce compressive stresses adjacent the center of the blade and tensile stresses adjacent the lateral edges, so that the blade as sumes a transversely curved configuration in which the radius of the transverse curvature progressively increases from adjacent the reactor 108 toward the outer end 102.

The reactor 108 is connected with the top wall 66 of the housing by an adjusting screw 126. The screw has a shank portion 128 which is received in a slot 130 in the top wall 66 of the housing. A shoulder 132 on the screw bears against the under surface of the top wall 66 and cooperates with the head of the screw to prevent longitudinal displacement of the screw in the slot. The shank 128, however, is free to slide along the slot 130 to accommodate changes in the position of the reactor 108 and the tension bar 114. If necessary, suitable means can be provided on the screw 126 to resist accidental rotation of the screw due to vibration.

As shown in FIGS. 5 and 6, a base lever 134 is pivotally connected with the base plate 16 by a hinge 136. A latch 138 is provided on the surface of the ski 4 in alignment with a socket 140 in the base lever 134. The latch 138 includes a latch bar that rotates about its supporting post, so that when it is in the position shown in FIG. 6, the latch prevents the outer end of the base lever 134 from swinging away from the surface of the ski. When the latch bar is in the position shown in FIG. 11, it is aligned with enlarged portions of the socket 140 which allow the bar to pass freely through the base lever 134, so that the bar no longer restricts swinging movement of the lever 134 relative to the ski.

lower section 152 of the lever. The tongue 156 has notches 158 along the opposite lateral edges and the blade 100 has a longitudinal key slot 160 of substantially the same width as the distance separating the notches 158. Thus, the notches in the tongue 1S6 support the outer end of the blade 102 and restrict its movement relative to the tongue 156.

As shown in FIG. 7, the upper section 150 of therelease lever has an opening 162 which is aligned with the enlarged portion of the key slot 160 in the blade 100. The lower section 152 of the release lever has an opening 164 corresponding to the key slot in the blade. A tab 166 extends downwardly from the central portion 148 of the release lever and is aligned with a slot 168 in the base lever 134. The tab 166 centers the release lever with respect to the base lever. Extensions 170 of the arms 144 project under the base lever 134 and retain the base lever between the extensions 170 and the curved end 154 of the release lever.

A prop 172 for temporarily supporting the blade for cocking is movable from an operative position to a retracted position by the blade. The prop 172 has a pair of arms 174 (FIG. 5) that bear against the lower surface of the blade 100. The arms 174 are secured to the blade by welding or other suitable means, so that when the blade snaps from the position shown in FIG. 5 to the position shown in FIG. 10, the prop 172 swings upper surface of the base lever 134. Also, when the blade snaps back to the position shown in FIG. 5, the prop 172 is retracted. The prop 172 is shown in FIGS. and 11 at the rearward end of the rack 176. This position corresponds to a low preload on the blade imposed by the screw 126. When the screw 126 is adjusted for a high preload, the prop 172 is adjacent the forward end of the rack 176.

The housing 62 is enclosed by a cover 177. The cover has an opening through which the adjusting screw 126 is accessible, and the cover is secured on the housing by screws 178 (FIG. 8). An arcuate slot 179 is provided in the side of the cover through which the position of the shaft 60 can be observed.

The heel binding unit is capable of operating either in an automatic mode in which the snap action blade 100 is cocked by the movement of the step lever down- I wardly from the position shown in FIG. 10 to the position shown in FIG. 5; or in a manual mode in which the housing is displaced from the position shown in FIG. 1 1 while the step lever 48 moves downwardly to the positionshown in FIG. 5. In the manual mode, the blade is cocked by swinging the base lever 134 downwardly to the position shown in FIG. 5.

When the heel binding unit isadjusted for automatic operation, the latch 138 is turned to the position shown in FIG. 6 to hold the base lever 134 against the surface of the ski. When the skier places the heel of his boot against the step lever 43, the spring 52 acts as a guide for the heel and downward displacement of the heel slides the bar 46 along the slot 44 toward the horizontal leg of the slot. Just as the bar moves into the horizontal leg, the upward force applied to the blade by the prop 172 and the downward displacement of the tension bar 114 causes the blade 100 to snap over from the released position shown in FIG. 10 to the clamping position shown in FIG. 5. As the blade snaps, the prop 172 swings upwardly out of engagement with the rack 174 and the bar 46 is displaced rearwardly to the position downwardly to engage a rack 176 provided on the shown in FIG. 5 while the roller 94 surfaces 98 on the heel of the boot. v

For operation of the heel binding unitin its manual mode, the latch 138 is rotated degrees frorn' the positon shown in FIG. 6 to align the latch bar'with the enlarged portions of the socket 140, therebyallowing the base lever 134 to swing away from theski'surface. When the blade is in the released positi omthe com ponents of the binding are initially in theposition shown in FIG. 11. When the heel of the'boot is applied to the step lever 48, the bar 46 moves downwardly alongthe slot 44 until it is positioned at the forward end of the horizontal leg. This movement brings the roller 94 into engagement with the cam surface 98 on the heel of the boot, but ths spring force of the blade 100 is not applied to the boot because the lever 134 remainsapproximately in the position shown in FIG. 11, although the release lever 142 slides forwardly along the base lever 134 to accommodate swinging movement of the housing 62. The skier then places the end of his ski pole in the socket and presses down, thereby causing the base lever 134 to rotate about the hinge 136 until the blade 100 snaps over the position shown in FIG. 5.

The manual mode allows the skier to utilize a higher preload on the blade than is possible in the automatic cocking mode. As previously stated, the prop pole 172 is positioned at the forward end of the rack 176 when the screw 126 is adjusted for a high preload on the blade. Consequently, when the base lever 134 swings downwardly in response to the force applied by the skier at the outer end of the lever 134, the portion of the rack that overhangs forwardly of the hinge 136 swings upwardly. This movement of the rack is transmitted to the prop pole, and in turn is transmitted to the blade to provide sufficient displacement of the blade edge 102 relative to the blade to the blade tabs 122 to cause the blade to snap over to the clamping position, even though it has a high .preload.

In either automatic mode or manual mode, the extensions 170 on the release lever slide along the opposite edges of the base lever 134, which, as shown in FIG. 6, are tapered outwardly. This allows lateral clearance beengages the cam 1 tween the release lever and the base lever so that the release lever moves freely along the base lever when the blade is snapped over to the released position, but when the blade is in the clamping position, the extensions 170 fit closely against the edges of the lever 134 as shown in FIG. 6.

The heel binding can be released manually from the clamping position, as shown in FIG. 5, by inserting the end of a ski pole through the opening 162 in the upper section of the release lever 142. The end of the pole passes through the key slot in the blade and through the opening in the lower section 152. With the tip of the pole resting on the surface of the ski, a force can be applied tending to rotate the lever 142 about the end 154 in a counterclockwise direction, as viewed in FIG. 5, pulling forward on the upper end of the ski pole. The abutment 171 on the base lever 134 serves as the fulcrum for the pole and there is sufficient leverage to overcome the force of the spring blade 100 easily. This causes the binding to release and assume the position shown in FIG. 10 or in FIG. 11, according to the position of the latch 138.

The pole socket in the release lever can also be used for cocking the spring blade. The pole bears against the tab 166 and agaisnt the tongue 156, and by swinging the upper end of the ski pole rearwardly, the blade snaps over to its clamping position. When cocking the unit in this manner, the prop 144 is not used. Manual cocking of the heel binding is necessary when high preload forces are imposed on the blade, and is a convenient way of attaching the bindings in soft snow, or where the ground conditions made it difficult to step on the lever 48 firmly enough to cock the unit.

The toe binding unit 6 in accordance with one preferred embodiment of this invention is illustrated in FIGS. 1, 2 and 12 to 15. The toe binding unit 6 includes a base 180 which is secured to the ski 4 by a pair of screws 182. The base 180 has an upright center plate 184 and a clamping head 186 is hingedly supported on the center plate 184 by a pin 188. The clamping head 186 includes a pair of arms 190 which project diagonally rearward. Each arm has an upwardly projecting flange 192 that forms a guide for the toe portion 94 of the boot 2. As shown in FIGS. 12 and 13, the toe 194 has a pair of sockets 196 in which the flanges 192 are received. The flanges 192 hold the toe of the boot against lateral displacement relative to the toe binding unit and serve to center the toe of the boot on the ski.

, At the outer end of each arm, there is a slot 198 and a toe support 200 is hingedly connected to the arms 190 by curved tabs 202 which are looped through the slots 198. As shown in FIG. 12, the tabs 202 rest on the surface of the ski 4. Support pads 204 are provided on the toe support 200. The pads are positioned at the extreme ends of the toe support 200 for stability. The pads have a transverse edge 205, from which the tabs 202 extend downwardly. As shown in FIG. 12, the sole of the boot 2 rests directly on the pads 204.

The clamping head 186 includes a rearwardly projecting shank portion which terminates in a sleeve 208. The sleeve 208 is internally threaded to receive a screw 210. As shown in FIG. 12, the screw 210 has an enlarged head which projects rearwardly to overlap the front edge of the toe portion 194 of the boot. By turning the screw 210, the height of the head relative to the pads 204 can be adjusted to accommodate boot soles of different thickness. A wire 212 is coiled on the shank 106. A series of holes 214 are provided in the clamping head 186, shown in FIG. 12, and these holes are aligned with corresponding holes in the mounting plate 184 for selective insertion of the wire 212 in one of the holes 214.

The toe binding unit 6 is capable of releasing the toe of the boot when the heel has been displaced laterally a sufficient distance for release at the heel. The toe binding unit 6 also releases when a force of predetermined magnitude is applied upwardly in the direction of the arrow 12 in FIG. 2.

When torsional forces are imposed between the ski 4 and the boot2, they are resisted at the toe binding unit by the flanges 192 and at the heel by the roller 94 which is biased toward the center of the cam surfaces 98 (FIG. 8). As the heel is displaced laterally, it turns the rollers 30 and 32 which impose substantially no frictional resistance and it turns the roller 94 which is progressively displaced upwardly along one of the cam surfaces 98. If sufficient lateral force is applied at the heel, the spring bias of the blade 100 will be overcome and the heel binding will release the heel by swinging the roller 94 upwardly away from the cam surfaces 98. As the heel of the boot swings laterally, for example, in the direction of the upper arrow 14 in FIG. 1, the toe of the boot pivots about the right-hand flange .192. Since the torsional force is applied at the heel, and the length of the boot is substantially greater than the distance separating the right-hand flange 192 from the left-hand pad 204, and the underside of the clamping screw 210, then whatever frictional resistance is imposed, is easily overcome. Since the engagement between the boot and the rear binding is entirely through rolling contact, there is substantially no frictional resistance to lateral displacement at-the heel, and although there is frictional resistance at the toe,;sufficient leverage is applied to overcome readily the frictional resistance. Thus, the toe and heel binding effectively and reliably release the boot when a torsional force of predetermined magnitude is applied, and since the release is uneffected by friction, the force level at which release occurs remains substantially constant regardless of changes in the weight applied by the skier on the supporting surfaces.

Ordinarily, the cantilever loading applied on the boot toe is substantially greater than the forces that would normally be applied to the boot in skiing with conventional bindings. The clamping force applied downwardly by the screw would be of the order of twice the weight of the skier.

A second preferred embodiment of the toe binding unit and heel binding unit is illustrated in FIGS. 16 to 36. Referring to FIGS. 16 and 17, the toe binding unit 220 and heel binding unit 222 are shown as mounted on a conventional ski 224. A ski boot 226 is mounted in the binding units and held securely on the ski 224.

The boot 226 is provided with a toe clip 228 and a heel plate 230 which cooperate with the respective toe and heel binding units. Of course, the toe clip and heel plate may be formed integrally with the boot, if desired.

Referring to FIGS. 18 to 23, the toe binding unit includes a base plate 232 (FIG. 20) which is secured on the surface of the ski 224 by a pair of screws 234 and by a third screw 236 which extends through a hole formed in a rearwardly projecting tongue 238.

A toe support bracket 240 (FIG. 19) is assembled over the base plate 238. The toe bracket 240 includes a pair of raised toe pads 242 and a central ridge 244. The ridge 244 cooperates with a corresponding ridge 246 on the base plate 232 to maintain the bracket in alignment with the base plate. A toe clamping member 248 is secured to the toe bracket 240 by a pair of rivets 250. The toe clamping bracket 248 is secured to the base plate 232 by a rivet 252. The clamping member 248 includes a pair of lateal flanges 254 and a clamping porjection 256.

The boot toe clip 228 is secured on the toe of the boot by screws 258 extending through the holes 260. The clip 228 includes bearing plates 262 which cooperate with the pads 242. The boot toe clip also includes transverse abutment 264 which cooperates with the clamping projection 256 on the toe clamping member 248. As shown in FIG. 23, an adjusting screw 266 is threaded into the base plate 232. The head of the screw 266 limits movement of the clamping projection 256 in an upward direction away from the pads 242. Thus, the adjusting screw 266 limits the distance separating the underside of the projection 256 from the upper surface of the pads 242. Preferably, the separation between the projection 256 and the pads 242 is slightly less than the vertical distance between the lower surface of the bearing plates 262 and the clamping abutment 264 to provide cantilever loading of the boot toe, as explained previously in the embodiment of FIGS. 12 to 15. The degree of cantilever loading can be adjusted by turning the screw 266.

The base 247 of the clamping member 248 (FIG. 22)

is formed with an upward curvature between the rivet 242 and the vertically raised portion of the member 248. The toe bracket 240 is formed with a downward curvature between the central ridge 244 and the pads 242. The curvature of the bracket 240 is greater than that shown in FIG. 22. The adjusting screw 266 urges the clamping bracket 248 downwardly toward the surface of the ski, thereby flattening the arched toe bracket 240 and straightening the base 247 of the clamping bracket 248. The stress on these two members imposes an axial load on the adjusting screw 266 to keep it locked in the adjusted position.

When the toe binding clip 228 is clamped in the toe binding units, as shown in FIG. 23, the rear faces of the flanges 254 engages cam 268 formed in the lower front portion of the boot toe clip 258. The cams 268 cooperate with the flanges 254 to slide the bearing plates 262 across the pads 242 as the heel of the boot is displaced laterally while releasing at the heel.

Referring to FIGS. 24 to 36, the second embodiment of the heel binding unit includes a base 270 which is secured to the surface of the ski by a screw 272 (FIG. 28) which is received in a longitudinal slot 274 in the base 270. A pair of studs 276 (FIGS. 26 and 35) are screwed into the ski and project into longitudinal slots 278 in the base 270. .Cap screws 280 extend through lock washers 281 and are threaded into the respective studs 276 to lock the base at a selected longitudinal position on the surface of the ski.

I At the forward end of the base 270, a pair of support rollers 282 are joumalled for rotation in bearing block 284. The central axis of each roller 282 is angularly offset, as shown in FIG. 28, so that the surface of the roller is more closely aligned with the direction of movement of the heel during lateral release. Central axes of the rollers 282 are aligned in a horizontal plane in order to support the heel evenly on the rollers.

The heel of the boot is provided with a plate 230 which is secured to the heel by screws 286-extending through screw holes 288in the side of the plate. The plate wraps around the heel of the boot and has upper and lower cam surfaces 290 and 292. respectively; As shown in FIGS. 24 and 26, the rollers 282 support the heel of the boot substantially parallel with the surface of the ski. The cam surface 292 has peaks 294 which are aligned with the rollers 282 when the heel of the boot is centered over the ski.

The cam surface 292 engages the respective rollers at locations on opposite sides of the peaks 294, as

shown in FIG. 24. If, for example, a skier is edging his ski along the left-hand edge, as viewed in FIG. 24, a lateral force is applied to the boot heel tending to displace the heel toward the right relative to the rollers 282. The skier's weight is also applying a downward force. The

resultant of the lateral force and the vertical force, as

well as other forces in the system, produces a reaction force at the point of 'tangency between the rollers 282 and the cam 292. The axis A intersects this point of tangency and extends perpendicular to the cam surface 292.

As long as the resultant force vector acts in a direction to the right of the axis A, the force urges the cam surface 292 and the rollers 282 more tightly together. When the resultant force vector acts in a direction 'to the left of the axis A, the heel plate is urged toward the right, but displacement of the heel plate is resisted by the main spring as the roller 282 rolls along the cam surface. An exemplary resultant force F is shown in FIG. 24 acting in a direction to retain the heel in the binding, and a resultant force F is shown actingin a direction tending to displace the heel laterally toward release. By appropriately shaping the cam surfaces, the desired force relationships for release can be selected.

A transverse shaft 296 is mounted in the base 270 and is held in place by set screws 298 at opposite ends, as shown in FIGS. 33 and 34. A yoke 300 is formed with sleeves 302 at its lower end for receiving the shaft 296. The sleeves 302 allow the yoke to swing freely about the shaft 296. The upper end of the yoke 300 is also provided with sleeves 304 and a pivot shaft 306 is received in the sleeves 304. Lock rings 308 on the shaft prevent the shaft from movingaxially, but allow the shaft and the yoke 300 to turn freely relative to each other.

The yoke 300 is given a C shape as shown in FIG. 26,

so that'it becomes effectively a spring. In this way.

spring energy that is required to release the binding includes the energy in the yoke 300 as well as the energy in the main spring blade. This applies either to vertical or lateral release. The yoke 300 provides shock abosrbing capacity which supplements the shock absorbing effect of the main spring blade. The spring constant of the yoke 300 due to its shape is preferably selected to provide release energy that is proportional to release force. Another advantage of the compliant yoke shape is that it facilitates assembly of the binding and the pre- Ioad force becomes less critical.

As shown in FIG. 26, the heel binding unit includes a housing 310. At the forward end of the housing, a re lease roller 312 is journalled for rotation about a screw 314 which also secures the release roller to the front end wall 316 of the housing 310. The housing 310 is shown in detail in FIG. 36. The opposite side walls 318 are arranged in substantially parallel relation and a rider 320 is mounted between and guided by the upper and lower edges of the side walls 318. As shown in FIG. 33, the rider 320 has a transverse bore 322 through which the shaft 306 extends. The rider also has a central slot and screw threads in the slot receive an adjusting screw 324. The rider is deformed after cutting the slot to provide a spring load, on the screw when the rider is mounted between the side walls. The head of the adjusting screw 324 has a groove 325 which bears agaisnt the opposite sides of the rear wall 326 of the housing 310 (FIG. 26) to hold the screw against axial displacement. By turning the screw 324, the rider 320 slides along the side walls 318, carrying the shaft 306 with it. I

Resistance to upper movement of the reaction roller 312 is provided by a resiliently flexible snap action blade 328. As shown in FIG. 29, the blade projects rearwardly from the housing 310 and the outer end is supportedon a tab 330 projecting upwardly from the endwise movement of the members relative to each other and the members fit together to form coplanar flanges and each flagne has a notch 338. Each reactor member 334 is turned outwrdly at the forward end and is provided with a slot 340. As shown in FIGS. 29 and 30, the blade 328 has a curved edge 342 and has forwardly extending leg portions 344. Each leg portion 344 has a notch 346.

Referring to FIG. 32, the members 334 are held together as a unit by a screw 354 which has a nut 355 threaded on one end. The members 334 of the bracket are hinged about the rearward end and bear on the surfaces 357. The inclined surfaces 357 urge the members into engagement with each other when the forward end of the members 334 are forced outwardly by the spring blade which is mounted in the slot 340.

The blade 328 is mounted on the reactor 332 by aligning the curved edge 342 with the notches 338 in the reactor and inserting the leg portions 334 through the slots 340 while compressing the leg portions toward each other. When the notches 346 are aligned with the slots 340, the legs are released, thereby allowing the spring forces in the blade 328 to lock the blade in the slots 340 while applying stresses to the blade causing the portion of the blade between the curved edge 342 and the mounting tab 330 to assume a transversely curve. The blade 328 is bistable and when the blade is in the position shown in FIG. 26, a downward force applied through the notches 338 causes deflection of the outer end of the blade progressively toward the curved edge 342, until the blade snaps over to the opposite stable position, as previously described. The characteristics of the snap action blade are described more fully in my U.S. Pat. No. 3,543,595, issued Dec. 1, 1970.

The reactor 332 is secured to the housing 310 by a pin 348 which extends through aligned holes in the sides 318 of the housing and through holes 350 in each member of the reactor. Another pin 352 extends through the side walls 318 at the front of the housing and is received in the slots 340 formed in the reactor. A screw 354 holds the members 334 of the reactor together and resists the outward forces imposed by the spring blade 328.

When the blade 328 is mounted on the reactor 332 4 the screw 354 adjusts the spacing between the sides of the reactor members to apply preloading on the blade 328. By adjusting the distance between the head of the screw 354 and the nut 355, adjustments can be made to calibrate the blade 328. Furthermore, since the blade and: reactor form a unitary device, when assembled together, the blade can' be calibrated as a unit before assembly with the housing, thereby simplifying assembly process. After calibration, the nut 355 may be welded to the side of the reactor.

Manual release of the heel binding unit is accomplished by means of? an operating. lever 356 which: is pivotally mounted on the screw 354 (FIG. 30-). A pair of side links 358 are pivotally mounted on: pins 360 projfecting outwardly from the sides of the lever 356: The" lower endof each link 358 is supported on: the base 276 by a rivet 362.

The handle 356 is pivotally mounted on the screw 354? and extends rearwardly. When the ski is impacted downwardly for example by stamping the ski: on the ground, the inertia of the handle urges the handle to swing clockwise, as viewed in@ FIG. 261- Movement of the handle downwardly urges the rear end of'th'e read tor 332 to swing upwardl thereby counteracting unintentional snapping of the blade 328 from the position shown in FIG. 26 to the released position. Thus, the binding is substantillly insensitiveto shock loading.

In order to maintain the front wall 316 of the housing in position to engagea boot heel when the spring blade 328 is in the released position, a captivating spring 364 (FIG. 26) is provided. The spring 364 extends over the transverse shaft 296 and the rearward end of the s rin overlies the rivet 372 which supports the side links 358. The forward end of the spring-3.64 projects upwardly on the rearward side of the front wall 316 and projects between the side walls 318.When the spring blade 328 is in the released position, the forward end of the spring 364 bears against the rear side of the front wall 316.

The captivating spring 364 has notches 366 which prevent downward movement of the serving 316. The spring notches 366 serve the function of supporting the housing when snapping the blade 328 from a released configuration to the configuration shown in FIG. 26 by swinging the handle 356 downwardly. When releasing the rear bindin by ulling up on the handle, the tab 330 engages the upper surface of the blade 328 to facilitate release. The lot 329 (FIG. 26 in the blade cooperates with the tab 330 druing release to limit forward movement of the housing 310 when the roller 312 is not in engagement with a heel plate.

The captivating spring 364 normally urges the roller 312 forwardly. Usually, this is sufficient to ensure engagernent of the heel plate230 by the roller. If ice in the toe or heel binding interfers with proper seating of the boot in theibinding", downward movement of the handle 356 applies a forward component of force to the housing 310 due to the inclined position of the yoke 330. While moving from a released to a clamping position, the front wall 316 of thehousing engages the rear the ice and to seat the heel plate on the rollers 282. The

curved shape of the yoke 300' provides suffic'ient compliance to" permit the roller 312 to ride over the cam surface 290' until the surface is seated in the groove 313 formed in the roller 312. This insures proper seating of the boot in the heel binding.

In operation, the top clip 228 and the heel clip 230 are secured on the boot 226 in the proper position to cooperate with the front and rear binding units. The heel binding. unit is" initially released. In the released position, the operating lever 356 is' raised from the position shown in FIG. 26' and the reactor 332 is tilted downwardly about the pivot shaft 306- with the spring blade @28 curved' in the direction pposite to that shownin FIG.- 26tin thisposition', the spring blade 328 does not provide any substantial resistance to the upward movement of the release roller 312. The toe of the Boot is first insertedforwardly into the toe binding unit, as i lhi's'tf i ated in FIG. 21 Forward movement of the toe continues until the flanges 254 engage the cams 268? on the toe'elip. l n t'h'e courseof' moving to this position, the clam'pinglprojectio'n 2'56 engagesthe clamping abutment 264, assh'own in- FIG. 23". The bearing pl'ates' 

1. A ski binding unit for temporarily clamping the heel of a boot on a ski comprising: a base adapted for mounting on the surface of a ski, said base including supporting means adjacent one end arranged to engage and support the heel of a ski boot, lever means spaced above said base and including a transverse pivot shaft, yoke means mounted at one end for swinging about a transverse axis on said base and at the opposite end mounted on said pivot shaft, a clamping member, said clamping member being mounted on said lever means and being spaced longitudinally from said pivot shaft and being movable away from said boot supporting means upon swinging of said lever means about said pivot shaft in one direction, bistable spring means connected between a rearward portion of said lever means and said base, said spring means having a first position providing progressively increasing resistance to swinging of said lever means in said one direction until said clamping member has moved a predetermined distance away from said support means, said spring means having a second position urging said lever means to swing about said pivot shaft in a direction opposite to said one direction and operating means for selectively displacing said spring means from said first position to said second position.
 2. The ski binding unit according to claim 1 wherein said supporting means includes a pair of support rollers mounted for rotation about fixed axes extending substantially longitudinally of said base.
 3. The ski binding unit according to claim 2 wherein said clamping member includes a clamping roller mounted for rotation about an axis extending substantially longitudinally of said lever means, said clamping roller having a substantially conical cam surface.
 4. The ski binding unit according to claim 3 including in combination a rigid heel clip, means for securing said heel clip to a ski boot, said heel clip including a bottom surface and a cam projecting upwardly from said bottom surface, said bottom surface including recesses aligned with said support rollers and said cam having a recess aligned with said clamping roller, whereby lateral displacement of said heel clip relative to said base displaces said clamping roller away from said base.
 5. The ski binding unit according to claim 1 wherein said lever means is in the form of a housing having a pair of spaced side walls and includes a rider supported between said side walls, said pivot shaft being journalled in said rider, and including screw means for selectively displacing said rider along said housing to change the length of the lever arm between said pivot shaft and said clamping member, respectively.
 6. The ski binding unit according to claim 1 wherein said yoke means is resiliently extensible in response to tension, whereby release energy may be stored in the yoke means in addition to release energy in the spring means.
 7. The ski binding unit according to claim 1 wherein said spring means includes a thin resilient spring blade having an outer end connected with said base, said blade having a curved edge mounted on said lever means, said lever means including means stressing said blade to assume a bistable three-dimensional configuration, in one of said stable configurations corresponding to said first spring position said spring balde urges said clamping element toward said support means and in the other of said stable configurations corresponding to said second spring position said spring blade urges said clamping means away from said support means, said operating means including an operating handle mounted on said lever means for selectively snapping said spring blade from one stable configuration to the other.
 8. The ski binding unit according to claim 7 including a pair of side links pivotally connected between said base and said lever means, and wherein said operating handle is pivoted on said lever means and arranged to apply a force on said blade adjacent said curved edge selectively in a direction either toward or away from said base, whereby said blade snaps over from one configuration to the other.
 9. In a ski binding unit of the type having a base and a pivoted lever mounted on said base with a clamping member on the lever for engaging a portion of a ski boot, and a spring for yieldably resisting movement of said clamping member away from the base, the improvement wherein said spring comprises a thin resiliently flexible blade having a Slot extending longitudinally from one end and terminating in a transversely curved edge, the portions between the lateral edges of said blade and the edges of said slot defining leg portions capable of flexing toward each other, and including reactor means on said lever supporting said blade adjacent said curved edge, said reactor means also including a pair of oppositely facing abutments spaced longitudinally from said curved edge, said blade leg portions being in engagement with said abutments, said abutments being spaced apart from each other a distance less than the separation between corresponding locations on said leg portions when said blade is flat, thereby flexing said blade to assume a transversely curved, bistable configuration in the portion of the blade between said curved edge and the opposite end of said blade, whereby said blade provides progressively increasing resistance to displacement of said clamping member until said blade snaps over to the opposite bistable configuration.
 10. The ski binding unit according to claim 9 wherein said reactor means includes a body portion extending longitudinally of said blade in said slot, said reactor means having a pair of lateral flanges adjacent said curved edge, said flanges each having a notch receiving said curved edge and supporting said blade thereby.
 11. The ski binding unit according to claim 9 wherein said reactor means extends longitudinally of said blade and is received in said slot, said reactor means including a pair of outwardly extending projections, said projections having lateral slots forming said abutments therein, said blade leg portions each having outwardly facing notches therein, said blade leg portions being received in said reactor slots and said slots being aligned with said blade notches, whereby said blade is secured on said reactor means.
 12. The ski binding unit according to claim 9 wherein said reactor means is aligned with said lever means and includes an operating handle pivotally mounted on said lever means, and pivoted link means between said base and said handle, said link means cooperating with said handle to apply force to said blade while said handle is operated, whereby moving said handle in one direction applies a force on said blade adjacent said curved edge to snap over said blade from one bistable configuration to the other.
 13. The ski binding unit according to claim 9 wherein said reactor means includes a pair of reactor members, means connecting said members together adjacent said curved edge of said blade, said oppositely facing abutments being provided on the respective ones of said members, and means securing said members together with a fixed distance between said abutments.
 14. The ski binding unit according to claim 13, wherein said members each include notch means receiving and supporting said curved edge of said blade.
 15. The ski binding unit according to claim 13 wherein said means connecting said reactor members together includes a hinge, and said reactor means includes adjustment means for selectively changing said fixed distance between said abutments by swinging said members relative to each other about said hinge, whereby the preload on said blade may be adjusted after said blade is assembled on said reactor members. 